Fears that switching to genetically modified (GMO) crops could harm the habitat of wild birds, insects and other plants may be overblown, British scientists who have developed a forecasting model say.
The model developed by Reading University's Centre for Agri-Environmental Research also suggested government policy to promote a recovery in farmland bird populations may fail to deliver its goal.
There have been concerns that GMO crops which are herbicide tolerant would hurt biodiversity as fewer weeds could threaten spiders and insects as well as the birds which feed on them.
Thirty-nine farmland birds could be threatened by a switch to GMO herbicide-tolerant sugar beet and rapeseed but with only one species, the meadow pipit, is the change likely to move it into a more threatened category, the scientists concluded.
"It appears that replacing equivalent conventional crops in the current agricultural landscape with GMO herbicide tolerant crops would only have a limited effect (on farm birds)," the scientists said in a paper published by Science magazine.
The paper also concluded that a major UK environmental scheme aimed at reversing a decline in farmland birds may not deliver its objectives as its focus was on hedgerows and land at the edge of farms rather than cropped areas.
The scientists argued the main driver for the decline in farmland birds had been the loss of food and nesting habitats in the cropped areas of the agricultural landscape.
Farmland bird populations have almost halved since 1970 with agricultural intensification seen as the main reason. The British government has set a goal of reversing the long-term decline by 2020.
Reading University scientists believe their forecasting model can help governments protect biodiversity with agriculture set to undergo major changes over the next few years.
European Union agricultural reforms, an anticipated growth in biofuels, the prospect of more genetically modified crops and an increasing impact from climate change are among the factors likely to pose new threats to birds, insects and plants.